- 4-20% of patients with pulmonary TB have GU involvement
- Presentation: insidious malaise and LUTS (dysuria, hematuria)
- Pyuria and/or microscopic hematuria present in >90% of cases
- Harry pearl: 1/3 microscopic hematuria, 1/3 pyuria, 1/3 both!
- Dx is by symptoms, u/a findings, current/prior TB infection, and radiology
- Limited dx utility of urine/urethral AFB smear since commensals exist (e.g. my favorite NTM organism, M. smegmatis!)
- Can mimic pyelo
- Thickening and fixation of ureter = “Pipe stem ureter” (characteristic of TB)
- Radiology: Upper AND lower urinary tract involvement is characteristic of TB
- Calcifications, calyceal distortion, strictures
- Associated conditions: Interstitial nephritis, GN, secondary amyloid, obstructive uropathy
Thanks to Ali for bringing up a new diagnostic test called LF-LAM (lateral flow urine lipoarabinomannan assay) for detecting active TB in HIV-positive patients!
- 2016 Cochrane review:
- Low sensitivity for TB in HIV-positive pts whether used for screening or diagnosis
- Combo of LF-LAM with sputum micro may increase sensitivity but decreases specificity
- In HIV-positive pts with low CD4 counts who are seriously ill, LF-LAM may help with diagnosing TB
- Cochrane Database Syst Rev. 2016 May 10;5:CD011420. doi: 10.1002/14651858.CD011420.pub2.
Link to Evernote: